Guiyang.bai@honno-auto. com
86-13840589744
Swirl vortex flow meter for pure gas with built-in pressure and temperature compensation. DN15–DN200, 1–3600 m³/h, 4–20 mA/RS485/HART, Ex II CT6.
The HNF70 swirl vortex (vortex precession) flow meter measures clean gases. Its flow profile resembles a Venturi tube with a set of spiral guide vanes on the inlet side: entering gas is forced into an intense vortex, and in the diffusion section the vortex meets backflow and begins a second rotation, forming a gyroscopic vortex-precession phenomenon whose frequency is directly proportional to flow rate and unaffected by the fluid's physical properties or density. A dual detection element picks up the precession frequency; a pre-amplifier amplifies, filters and shapes the signal into a pulse proportional to flow. The microprocessor integrates this with temperature and pressure signals for real-time compensation and compressibility correction. The head integrates the flow probe, microprocessor and pressure/temperature sensors in one compact body; the dot-matrix LCD shows instantaneous and cumulative flow, pressure and temperature, with both working-condition and standard-condition volume flow displayed.
No mechanical moving parts, resistant to corrosion and stable in service. Dual detection technology strengthens the signal against vibration interference, and anti-vibration processing handles signals from vibration and pressure fluctuation. The head rotates 360° for easy installation; multiple physical-parameter alarm outputs are user-selectable, with real-time diary and fixed-interval recording.
Good fit: natural gas metering, city gas distribution, compressed air systems, industrial process gas, oil and gas field gas metering, chemical plant gas lines, glass and ceramics kiln gas, boiler gas feed, energy management and gas balancing, biogas and landfill gas, gas dosing systems, plant utility gas monitoring.
Choose HNF70 when:
You measure pure gas at pressure above 10 kPa and need compensated standard-condition volume flow.
The line has vibration or pressure fluctuation, and dual detection plus anti-vibration processing is required.
You want pulse, 4–20 mA, RS485 Modbus RTU, HART or IoT GPRS output, with DC or battery supply.
Confirm with us first when: the gas contains liquid droplets, dust or impurities, pressure is below 10 kPa, temperature exceeds the rating, or a pressure rating above the standard 4.0/1.6 MPa is required.
Spiral guide vanes force the incoming gas into an intense vortex; in the diffusion section backflow causes a second rotation and the gyroscopic precession. The precession frequency is proportional to flow rate and independent of density and physical properties. The dual detection element measures this secondary rotation frequency for good linearity over a wide flow range. After amplification, filtering and shaping, the pulse goes to the microprocessor together with temperature and pressure signals; the instrument tracks compensation and compressibility correction in real time and displays instantaneous flow, cumulative flow, temperature and pressure.
| Model | HNF70 — Swirl vortex (vortex precession) gas flow meter |
|---|---|
| Execution standard | GB/T 36241-2018 National Standard for Gas Swirl Vortex Flowmeters |
| Applicable medium | Pure gas with pressure above 10 kPa |
| Accuracy | Standard ±1.0 %R; high grade ±0.5 %R (accuracy class selectable in the code) |
| Range ratio | 1:10–1:20 |
| Nominal diameter | DN15, DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN125, DN150, DN200 |
| Nominal pressure | DN15–DN50 4.0 MPa; DN65–DN200 1.6 MPa; higher ratings on agreement |
| Flow range | 1–3600 m³/h overall; see range table by DN |
| Medium temperature | −20…+120 ℃ |
| Ambient conditions | Ambient −20…65 ℃; relative humidity 5–90 %; atmospheric pressure 86–106 kPa |
| Shell / movement material | Aluminium alloy or 304 |
| Connection | Flange connection |
| Supply voltage | 6–24 VDC, current ≤10 mA (RS485 current +0.6 mA); battery type 3.6 V lithium battery, 0.3 mA |
| Output signal | Pulse; 4–20 mA current; control signal; RS485 (Modbus RTU); HART; IoT GPRS |
| Transmission distance | Up to 1000 m from sensor to display instrument |
| Recording | Real-time diary recording and fixed-interval recording |
| Explosion protection | Ex II C T6 Gb |
| Protection class | IP65 |
| Electrical interface | M20×1.5 |
| Model | DN | Flow range (m³/h) | Working pressure (MPa) | Installation |
|---|---|---|---|---|
| HNF70-015 | DN15 | 0.04–0.25 | 1.6 / 4.0 | Flange |
| HNF70-020 | DN20 | 0.1–0.6 | 1.6 / 4.0 | Flange |
| HNF70-025 | DN25 | 0.2–1.2 | 1.6 / 4.0 | Flange |
| HNF70-032 | DN32 | 0.2–2 | 1.6 / 4.0 | Flange |
| HNF70-040 | DN40 | 0.6–6 | 1.6 / 4.0 | Flange |
| HNF70-050 | DN50 | 0.7–7 | 1.6 / 4.0 | Flange |
| HNF70-065 | DN65 | 1–10 | 1.6 | Flange |
| HNF70-080 | DN80 | 1.5–15 | 1.6 | Flange |
| HNF70-100 | DN100 | 2–20 | 1.6 | Flange |
| HNF70-125 | DN125 | 4–40 | 1.6 | Flange |
| HNF70-150 | DN150 | 7–70 | 1.6 | Flange |
| HNF70-200 | DN200 | 10–100 | 1.6 | Flange |
| Code segment | Code | Description |
|---|---|---|
| Nominal diameter | 004 / 006 / 010 … 250 / 300 | DN4, DN6, DN10 … DN250, DN300 |
| Meter functions and outputs | YA | Dual power supply, pulse output |
| YM | Dual power supply, two-wire 4–20 mA output | |
| YR | Dual power supply, RS485 communication output | |
| YMR | Dual power supply, 4–20 mA + 485 communication + one-click reset | |
| Usage environment | P | Ordinary type |
| B | Explosion-proof type | |
| Accuracy class | 1 | Level 0.5 |
| 2 | Level 1.0 | |
| Body material | A | 304 |
| B | 316 | |
| Impeller material | F | Stainless iron |
| C | 2Cr13 | |
| G | Duplex steel | |
| Pressure resistance level | 1 | 1.6 MPa |
| 2 | 2.5 MPa | |
| 4 | 4.0 MPa | |
| 6 | 6.3 MPa | |
| 10 | 10.0 MPa | |
| 16 | 16 MPa | |
| SL | Other special customization | |
| Turbine type | T | Wide-range turbine |
| B | Ordinary turbine |
Install in a straight pipe run with adequate upstream/downstream straight sections per the datasheet; avoid strong vibration, or isolate the meter from vibrating equipment.
The gas must be clean and dry; remove liquid droplets and dust upstream, and install a filter or separator where required.
Match body and impeller materials to the gas; confirm pressure rating against the actual process pressure.
The 360° rotatable head allows the display to face the reading direction; keep the converter within its ambient temperature range.
Natural gas: natural gas metering, city gas distribution, oil and gas field gas measurement.
Process and utility gas: compressed air, chemical plant gas lines, boiler gas feed, plant utility gas monitoring, gas dosing.
Industrial kilns: glass and ceramics kiln gas, energy management and gas balancing.
Renewable gas: biogas and landfill gas measurement.
Send: gas name and composition, normal flow and design flow, operating pressure and temperature, nominal size and pipeline bore, required output, supply, body/impeller material, pressure rating, and whether explosion-proof is needed. We will confirm the size and selection code before quoting.
Which clean gases suit this swirl meter?
It measures pure gas at pressure above 10 kPa, such as natural gas, compressed air, plant utility gas, boiler fuel gas, biogas and landfill gas. The gas should be free of liquid droplets, dust and large impurities.
Does it display compensated standard volume flow?
Yes. The head integrates pressure and temperature sensors; the microprocessor performs real-time compensation and compressibility correction, and the LCD shows both working-condition and standard-condition volume flow, cumulative flow, pressure and temperature.
Can it run from a lithium battery?
Yes. The battery type runs on a 3.6 V lithium battery at 0.3 mA; DC supply is 6–24 VDC at ≤10 mA. Dual-power versions combine the supply options in the code.
How do dual detection elements strengthen signals against vibration and pressure fluctuation?
The dual detection element picks up the precession frequency to improve signal strength, and anti-vibration processing filters interference caused by vibration and sudden pressure fluctuation; this keeps readings stable on vibrating or pulsating gas lines.
What pressure and temperature signals are integrated for real-time gas compensation?
Pressure and temperature sensors are built into the intelligent head together with the flow probe and microprocessor; their signals are integrated with the precession pulse for real-time tracking compensation and compressibility correction to standard conditions.
HNF70 Swirl Vortex Flow Meter Datasheet (PDF) — view all product manuals on our Download page »
Send us the gas, flow range, pressure and size. We will confirm the selection code before we quote.
Send us your application details »
Contact: HongNuo
Phone: 13840589744
Tel: 86-13840589744
Email: Guiyang.bai@honno-auto. com
Add: Zhongguancun Innovation Center, No. 28 Huahai Road, Shenyang Economic and Technological Development Zone, Liaoning Province
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